<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>AJAX</title>
</head>
<body>
    <script>
        function sendAJAX(url){
            return new Promise((resolve, reject) => {
                const xhr = new XMLHttpRequest();
                xhr.responseType = 'json';
                xhr.open('GET',url);
                xhr.send();
                xhr.onreadystatechange = function(){
                    if(xhr.readyState === 4){
                        if(xhr.status >= 200 && xhr.status < 300){
                            resolve(xhr.response);
                        }else{
                            reject(xhr.status);
                        }
                    }
                }
            })
        }
        // sendAJAX('https://api.apiopen.top/getJoke').then(value => {
        //     console.log(value);
        // }, reason => {
        //     console.warn(reason);
        // })

        async function main(){
            try{
                let res = await sendAJAX('https://api.apiopen.top/getJoke');
                console.log(res);
            }catch(e){
                console.warn(e);
            }
        }
        main();
    </script>
</body>
</html>